1. Field of the Invention
This invention relates to boat fenders, and more particularly to a system including a fender which is rotatable on a spindle extending in a lateral arm detachably connected to a locking assembly permanently attached to the stem or gunwale of a watercraft.
2. Description of the Related Art
The purpose of a boat fender or bumper is to protect the stem, transom, hull, gunwale or bonding flange of a boat from being damaged when moored to a fixed or floating dock, slip, pier, piling or similar structure. As used herein, "fender" means a device which hangs over a stem or fantail or a gunwale, while "bumper" means a device, similar to a car bumper, attached to a gunwale, hull, stem or fantail. A fender or bumper also protects the mooring structure from being damaged by the boat. A moored boat does not remain stationary but floats up and down and back and forth in the water while banging, bumping and rubbing up against the mooring structure. As the amplitude and frequency of the waves increase, the pitching and rolling of the boat intensifies, increasing the likelihood that the boat will be damaged. Consequently, many recreational boaters consider fenders or bumpers to be necessary accessories.
A type of boat fender in wide use is in the form of a cylindrical, elongated tube, rounded at both ends and filled either with air or a cellular foam inner core to cushion and absorb the shock of the boat bumping and banging against the mooring structure. Typically, the fender has a nylon cord at its upper end which is tied to a cleat on the gunwale. The fender simply hangs down from the gunwale to protect the hull, or hangs over the stem to protect the transom. A disadvantage of this type of fender when a boat is moored at a dock is that as the boat pitches and rolls, the fender does not stay in place but is turned sideways or lifted up by the waves onto the deck, allowing the boat to go under the dock where it can suffer serious damage. U.S. Pat. No. 4,841,893 to R. P. Ellison discloses a fender which does not pop up, even under rough conditions. The fender has a cylindrical body and upper and lower pairs of encircling rings which project outwardly. The rings contact both the hull and dock. Motion of the boat relative to the dock causes a rolling motion of the fender which is either horizontal or slightly upwardly arcuate. The limited fender motion is due to the parallel tracking caused by the two pairs of rings and the length of the line tying the fender off to a cleat on the gunwale.
U.S. Pat. No. 3,988,997 is directed to a boat fender which is particularly suitable for protecting a hull during passage through a canal lock. The fender is formed from two elongated sheets of flexible fluid-tight material sealed together about their peripheries and divided by a transverse seal into an upper and a lower compartment. The upper compartment contains air and is thicker than the lower compartment which is filled with a heavier substance such as water and serves solely as a weight to keep the fender from being blown about.
Another type of boat fender designed especially for low freeboard craft such as fishing boats and ski boats has an L-shape. A large cylindrical portion hangs down from the gunwale and an integrally attached and orthogonal neck portion has an aperture through which a nylon cord is inserted for attaching the neck to a cleat. Because such fenders hang freely, they are susceptible in rough water to being tossed up onto the gunwale, leaving the boat unprotected. U.S. Pat. No. 5,701,837 to T. E. Harvey discloses a boat bumper which overcomes this problem. A rectangular-shaped member with flexible battens has a flexible upper portion resting on the gunwale, and a deformable body which can be conformably positioned contiguous to the hull. U.S. Pat. No. 6,021,729 discloses a "fender" which according to the terminology used herein is a bumper. The J-shaped fender has a hook portion shaped to hook under the bond flange of a personal watercraft, allowing easy attachment and detachment, and at least one flex portion conformable to both the front hull and rear section of the craft.